220 Impact of Bump Feeding During Late Gestation on Reproductive Performance of Over-Conditioned Sows

Abstract Our objective was to evaluate the effect of bump-feeding during late gestation on reproductive performance of multiparous over-conditioned sows. A total of 220 PIC Camborough sows were assigned to one of three feeding levels in a completely randomized design. Caliper was individually collected at d 90 of gestation from a larger group of sows to assess body condition, and only sows from parity 1+ and considered over-conditioned by the sow caliper were selected for the study. Sows were equally balanced by parity (P1 and P2 as young, and P3+ as mature) when allocated to treatments. All sows were fed a common gestation diet containing 3.20 Mcal of metabolizable energy (ME) per kg and 0.56% standardized ileal digestible lysine, but feed drop-boxes were adjusted to different feeding levels according to treatment. Treatments consisted of 5.09 Mcal of ME/d (1.59 kg/d; CONTROL), 6.54 Mcal of ME/d (2.04 kg/d; 0.45kg-BUMP), or 8.00 Mcal of ME/d (2.49 kg/d; 0.90kg-BUMP); and fed to sows from d 90 of gestation until they were moved to the farrowing room. Sows were housed in crates during gestation. Sow body weight (BW) and caliper measurements were collected at pre-farrowing and weaning, and their difference was calculated. Additionally, post-farrowing 48h BW was predicted using the following equation: 48h post-farrow BW = -20.81 + (0.98 × pre-farrow BW). Total born, born alive (BA), stillborn (SB), and mummified were collected for each sow at farrowing. Individual piglet BW were recorded at birth, at cross-foster, and at weaning. Data were analyzed using a generalized linear model considering sow as the experimental unit. Models included treatment, parity group, and their interaction as fixed effects. Covariates were included if they were statistically significant and improved model fit. There was no treatment by parity group interaction for any response criteria. There was no evidence for differences between treatments for caliper at d 90 of gestation, caliper pre-farrow, caliper at weaning, or caliper change between d 90 to pre-farrow and pre-farrow to weaning (P >0.10; Table 1). Sows that received 0.90 kg-BUMP were marginally heavier at farrow than CONTROL sows (P < 0.10), with those receiving 0.45 kg-BUMP intermediate. CONTROL sows lost less BW during lactation compared with 0.45kg-BUMP sows (P < 0.05), with 0.90 kg-BUMP sows intermediate. Sows receiving 0.45kg-BUMP from d90 of gestation to farrowing had greater percentage BA piglets and decreased percent